Electrolytic cell.



T. GRISWOLD, JR. ELECTROLYTIC CELL. APPLIGATION FILED DEC. 7, 1907.

Patented Mar. 28, 1911.

a SHEEN-SHEET 1.

Hwww. i Q r m m on y I s 0 M 35H n ac s 5 a o T. GRISWOLD, JR.

ELECTROLYTIC CELL. APPLICATION FILED DEC. 7, 1901.

Patented Mar. 28, 1911.

3 SHEBTSSHEET 2.

wfleessear T. GRISWOLD, JR.

ELECTROLYTIC CELL. APPLICATION FILED DEC. 7,1907.

Patented Mar.28,1911.

3 SHBETSSHEBT 3.

Wzaases:

THOMAS GEISWOLD, JR., 0F MIDLAND, MICHIGAN.

ELECTROLYTIC CELL.

T 0 all whom 'it may concern:

I Be it known that I, THQMAS GRISWOLD, Jr., a citizen of the United States, resident of Midland, county of Midland, and State of Michigan, have invented a new and useful Improvement in Electrolytic Cells, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that-principle, so as to distinguish it from other inventions.

This invention relating, as indicated, to electrolytic cells, has more particular regard to the improvement of cells for the electrolysis of alkaline chlorids.

As is well known the electrolysis of compounds of the above general class forms the basis of a large chemical manufacturing industry, and for this reason many forms of cells have been prepared for the purpose noted and tried with varying degrees of success.- All, however, so far as I am aware have certain inherent characteristics preventing the realization in them of the ideal cell. As desirable characteristlcs such ideal cell should in its construction be of-siinple form, free from small details and complicated auxiliaries it should be readily adapted for the proposed use without involving expensive or intricate appurtenances; it should be constructed of inexpensive materials requiring but ordinary skill in its making and should. remain permanent under ordinary operative conditions; it should have reasonable bulk and weight, low ohmic resistance and high efficiency; it should be easy of access for inspection, cleaning, and renewal of parts be adaptable to series working, and require a minimum of attendance and supervision When in operation. It is with a view of realizing to a more perfect degree the above characteristics of the ideal cell that I have devised the present structure, involving the means hereinafter fully described and particularly pointed out in the claims. The annexed. drawings and the following description set forth in detail certain mechanism. embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle ofthe invention may be used.

In said annexed drawings: Figure 1 is a transverse cross-section of a single cell embodying, in simplest form, my invention;

Fig. 2 is a side elevation of such cell with a portion broken away; Fig. 2 is a view of Specification of Letters Patent.

Application filed December 7, 1907. Serial N 0. 405,497.

Patented Mar. 28, 1911.

Such cell, similar to Fig. 2, showing, however, a slight modification in form in one detail of the latters' construction; Fig. 3 1s a transverse cross-section of a cell corresponding with Fig. 1, but introducing a modification, in the form of a diaphragm separating such cell into two compartments; Fig. 4; shows the manner of assembling in a series, cells of the type illustrated in Fig. 8 Fig. 5 is a longitudinal vertical cross-section through the central element of acell, either of the type illustrated in Fig. 1, or Fig. 3, show ing incorporated therein means for regulating the. supply of electrolyte and the escape of gas; Fig. '6 is a transverse vertical crosssection of such cell element on the line (-36 Fig. 5; Fig. 7 is a transverse section of a series of cells embodying in conjunction with the features illustrated in Figs. 3 and 4 still other modifications in structure; Fig. 8 is, a side elevation with portions broken away, of a cell of the type illustrated in Fig. 7 and Fig. 9 is a plan view of the same, with part in section.

Eating first of all the simpler form of construction shown inFigs. 1 and 2, the cell will be scenj-to-eomprise a rectangular ring shaped,.or' perforated, member --S, which .i shall term a separator; Upon the opposite sides of such separator, which is made of suitable insulating material, are clamped blocksorplates; A C, of carbon. While I preferably employ carbon in graphitized form for such blocks or plates, other forms ingly,'-'Wheneverthe term carbon is hereinafter used in this connection it will be understood as including the various forms of carbon, including artificial graphitized carbon. These plates'A G laterally incloso the opening through separator b thereby forminga cell or chamber M for the reception of the electrolyte. Electric cur rent leads a c are clamped in contact with plates A C respectively by the same clamps It which thus hold the latter againstse nu'ator such clamps R consisting S1111- ply of wooden bars, the ends of which extend beyond the ends of the blocks in queslion and are joined together by threaded bolts 2'. Where separator S is of the annular form shown, chamber M will be a closed chamber st. for the opening. .9 provided for the introduction of the electrolyte as occasion may arise as wellas for escape of gas from the cell and an opening 8, northereof may] obviously be used; accordmally closed, for draining the cell of its contents. If however, an open cell is desired this result is easily accomplishedby making the separator of U-forni instead of a complete annulus or ring. A cell thus constructed is illustrated-in Fig. 2 and in referring to such member S herein as beplurality of such openings be provided.

In the use of the simple form of cell just described, the chamber M will be charged with the electrolyte, as, for example, a solution of common salt, and an electric current passed through it from A to C. Such plate A thus becomes the anode, upon the active face of which chlorin will be liberated, while plate C acts as the cathode'upon the active face of which hydrogen and caustic soda are liberated.

In the modified form of my invention illustrated in cross-section in Figs. 3 and 4, for both of which Fig. 2 serves as an end elevation, the active face of one of the carbon blocks, preferably the cathode C, is re cessed and a porous diaphragm D applied thereto being secured in place by being pressed in grooves at the edge of the block by means of key-pieces d. This diaphragm will accordingly be seen to divide the-cell into,two compartments, namely, the anode chamber M and the cathode chamber M The utility of a diaphragm thus separating the oxidizing from the reducing products of electrolysis, which in the form of cell shownin F 1g. 1, would mingle and recombme, 1s

well known, and needs no extended description here. The manner of its application and the details of the means for fastening or holding it to'the block will of course be determined by its nature.

In Fig. 4c, in addition to the modification just described, there is illustrated the manner in which my cell construction lends itself to a series arrangement. Between the. terminal anode and cathode elements A and C, respectively, to which the current leads a c are applied, are clamped additional separators S, diaphragms D, and intermediate graphiteblocks E, forming a series of divided cells ll/I M for which the blocks E act as anode on one face and cathode on the other. Current led to the terminal anode A leaves at the terminal cathode C after passing in succession through the several electrolytes, diaphragms and intermediate blocks. It is in this series arrangement that the greatutility of my improved construction of cells becomes apparent; for while, as will be obvious, the series of cells shown may be readily extended to any-desired numher, but two metallic electrical connections will be required to bring the current to and lead it from the series. No metallic connections whatever are required between the vat, cistern, or other form of container is required for the electrolyte; the area of active electrode surface is very-large when compared with the bulk and weight of the cell; the investment involved is low both for cells, owing to the character of material employed, and for room owing to high ratio of capacity to bulk; and the ohmic resistance may be reduced to a low figure by suitably shortening the electrode and electrolyte paths. A correspondingly high watt efliciency will be secured, giving increased output pen-unit cell, unit investment, and unit flow. Not only will the first cost of cells constructed as above described be very low owing to the great simplicity andcheapness of erection, but owing to the absence of all corrodible metallic parts, such as iron cathode, inter-cellular connectors, bolts, screws, clamps, and the like, the depreciation and stand by charges per unit capacity will be reduced to a minimum. 7

While for the particular use referred to for illustrative purposes the employment in the electrodes of some form of carbon, such as graphite, is preferred, it Will be understood that where for any reason a metal, such as iron, or indeed any other conducting substance, is desired, the same may be substituted while still retaining the major advanta es in construction above referred to. For t e separators, slate, glass, stoneware. ebonite, vulcanite, rubber, cement, wood and the like may be employed as found desirable or commercially feasible. Nor need the insulation of the electrode members A C be left dependent upon the insulating character of the material of the separator but a layer of packing 8 may be utilized for this purpose as also to effect a tight joint between the contacting surfaces of the members. A

similar latitude in the choice of diaphragm may be exercised,since, as before stated, it! specific construction of this element does not form a part of the present invention.

Along with the form of cell construction described above, any suitable arrangement for feeding and withdrawing the electrolyte or salt and taking off the gas may be employed to meet specific requirements. Where diaphragms D are used, as in Figs. 3 and 4,, an inlet opening 0 and outlet opening 0 are preferably supplied in connection with the recess in the active face of the cathode C that the liquid level in the corresponding com artment M of the cell may be regulate independently of the level in compart ment M or the rate of diffusion through diaphragm D. -And as to ducts 5- 8 for compartment M, while these are most conveniently formed in separator element .S,

rangement, .such arrangement being particularly adapted for use where the cells are assembled in series for the electrolysis of alkaline chlorids in the production of"chlo rin and caustic. For this use I preferably construct the separator of cement, a stoneware lute s and gas seal 8* for the escape of .the chlorin generated, and a tubular stonewarcconduit for the admission of brine respectively being cast in the body of the separator is shown. Raw electrolyte is permitted to drip from tap'l into the funnel shaped end a of such conduit, the level of the liquid therein being regulated by means of an adjustable tube .9 slidable in a stopper closing the outer end of a branch a" of the conduit. Such tube acts as an overflow for the excess of brine fed to the conduit as will be evident. lVhen the current first passes through the cell it is full of electrolyte but as the evolved gas accumulates in.

compartment M it depresses the surface of the'brine therein until it can bubble under the bridge 8 in the luted escape pipe si indicated, the two compartments-hf lVPintowhich the chambers M of the several cells are respectively divided may be fed and overflowedseparately, or anode chamber may be fed only, enough electrolyte being allowed to pass through the diapl'iragm to supply the cathode side from which it may escape as indicated at 6 Fig. 8.

The further modification in constructior of-the cell illustrated in Figs. 7, Sand 9,

bottom, with '65 relates to the form ofthe face of the electrodes of the several cells of the series. Thus the anode faces of the terminal electrode A and of intermediate electrode B a1 e extended so as to approach the cathode and shorten the current path through the electrolyte. The corresponding cathode faces arevertically grooved as at c, Fig. 5) so as" to p esent a fluted appearance, the ends of the grooves being intersected by transverse grooves c, Fig. 7 and being furthermore connected by small ducts c, at the top and transverse ducts of a" drilled through the block. Such transverse ducts &

are connec3ed at their ends by vertical crossv ducts 6 In operation, hydrogen gas, liberated on the face of the fluted cathode, rises in bubbles and effects its exit through the upper system of ducts 6 into the duct (4 whence it escapes above the liquid level therein by way of the open duct 6 The rising bubbles of gas cause a circulation of the cathode liquor up the face of the cathode and down the ducts 6 While in Fig. 7 the levels of. the electrolyte in the various anode and cathode compartments differ but slightly, it should be borne in mind that nevertheless the static pressure on opposite sides of the diaphragms may be made quite difi'crent as required by subjecting the electrolyte in the anode chambers to a greater controlled head.

Should the percolation and diffusion of the electrolyte through the blocks ofgraphite beiome objectionable because of their porosity, the pores of such blocks may be filled with an inert material unaffected by the electrolyte and adapted to impede its passage. In lieu of such remedy the blocks may be composed of two pieces in contact along a plane as indicated by line w-ac, Fig.

4, and a layer of similar inert material be interposed in the joint, sufficient area of uncovered surface being left 1n opposed locatlon to insure adequate electrlcah contact.

Such a contact ismuch superior from a practical standpoint to a metallic contact under like conditions of service.

In order to make a large cell, moderate sizes of graphite blocks may be utilized by clamping several of such blocks together transversely to'the direction of the electric such saving being particularly marked in series Working, wherein I avoid entirely the numerous intercellular electrical connection that are ordinarily required. At the same time a gain in reduced ohmic resistance is secured; By the elimination of connections in the places noted not only is a large item of e xpense for metallic elements of copper or the like obviated but at the same time,-

a soft gasket, or 0e owing to the, corrodible.character of such-T metallic elements, a largely increased degree of permanence is secured. *siiice suclrcom- ,ni'on materials are employed, the partsniay beenot only cheaply produced but also made age with .high watt efliciency, large output and compact plant requiring small attendance and supervision.

Other modes of applying the rinciple of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any one of the following-claims or the equivalent of such stated means be employed.

I therefore particularly point out and dis-.

tinctly claim as my invention 1. An electrolytic cell comprising two solid, non-'porous, carbon electrodes; and an annular separating member between said electrodes, whereby a chamber for the electrolyte is formed, the inner faces of the electrodes respectively forming an anode and a cathode.

An electrolytic cell comprising two solid, non-porous carbon electrodes; and an annular separating member clamped between said electrodes, whereby a chamber for the electrolyte is formed, the inner faces of the electrodes respectively forming an anode and a cathode, and said chamber being provided with openings for the inlet apd outlet of electrolyte and for the escape 0 as.

3 An electrolytic cell comprising two solid, non-porous, carbon electrodes; an annular separating member between said elec-- trodes, whereby a chamber for the electrolyte is formed, the inner faces'of the electrodes respmtively forming an anode and a cathode; and a porous diaphragm separating said chamber into two com artments.

4. A series of electrolytic eel s consisting of a plurality of solid, non-porous, bipolarelectrode members of homogeneous conducting material and insulating members alternately arranged and held together, each pair of electrode members, jointly with the interposed insulating member, forming a chamber for the reception of the electrolyte.

5. A series of electrolytic cells-consisting of a plurality of solid non-porous electrode members of homogeneous conducting ma terial' and insulating members disposed, one between each pair of electrode members, and adapted ,iointly therewith to form a chamberfo'r the reception of the electrolyte, the

terminal electrode members K respectively actmg as anode and cathode for the correspending chambers, and each of those intermediate between the ends acting as anode pair of conducting plates lyte, the terminal conducting -'plates respectively actingra's a'node and cathode for the corresponding chambers and each of those intermediate between the ends-acting 'as anode for the chamber on its one side and as cathode for the chamber on its other side.

7. A series of electrolyticeellsconsisting of a pluralityof solid, non-porous, carbon plates, annular plates of insulating material disposed one between each pair of conducting plates whereby chambers for the ,recepe tion of electrolyte are formed, means adapted to hold "said conducting and insulating plates together, and conductors held in contact with the two terminal conclamping ducting plates, such terminal .plates thus respectively acting as anode and cathode for the corresponding chambers and each of those intermediate between the ends acting as anode for the chamber on its dneside and ascathode for the chamber on its other side.

8. A series of electrolytic cells consisting of a plurality of solid. non-porous carbon plates, annular plates of insulatingv material disposed, one between eachpair of conducting-plates, whereby chambers -for the reception of electrolyte are formed, each suchinsulating plate being provided with ducts for ingress and egress ofthe electrolyte from the chamber formed thereby, clamping means adapted to hold said conducting and insulating plates together, and conductors held in contact with the two terminal conducting plates, such terminal plates thus respectively acting as anode and spondmg chambers, and each of those intermediate between the ends acting as anode for the chamber on its one side and as cathode for...the chamber on its other side.

cathode for the corre 9. .A series; of. electrolytic'cells eoi sisting #of ,pl-uralitynf solid non-porous carbon lates;"-'an"nular plates of insulating material isposed, one between each pair of conducting plates, whereby chambers, for the receptlon of electrolyte are formed, each such I insulating plate being respectively provided with ducts for the admission of the electrolyte to the chamber formed thereby and the escape of gas therefrom, .clamping means adapted to hold said conductin and .insu lating plates together, and con uctors held in ,contactwith the two terminal'conducting plates, such terminal acting as anode and cathode for t e t-replates thu's res ecti'yely of a plurality of solid nonporous carbon as anode ode for the chamber on its other side.

10. A series of electrolytic cells consisting of a plurality of solid non-porous carbon members and insulating members alternately arranged and held together, each pair of conducting members being adapted jointly with the interposed insulating member to form a chamber for the reception of the electrolyte; anda porous diaphragm interposed between adjacent conducting members and dividing the corresponding chamber into two compartments.

11. A series of electrolytic cells consisting members, insulating members disposed one between each pair of conducting members and adapted jointly therewith to form a chamber for the reception of the electrolyte, the terminal conducting members respectively acting as anode and cathode for the corresponding cell and each of those intermediate between the ends acting as anode for 'the cell on its one side and as cathode for the cell on its other, and a porous diaphragm interposed between each insulating member and one of the adjacent conducting members, the juxtaposed face of the latter being recessed, whereby. two compartments are formed in the cell.

12. A series of electrolytic cells consisting of a plurality of solidnon-porous carbon members, insulatingmembers disposed one betweeneach pair of conducting members and adapted jointly therewith to form achamber for the reception ofthe electrolyte, the terminal conducting members respectively acting as anode and cathode for the corresponding cell and eachjof those intermediate between the ends acting as anode for the cell on its one side and as cathode for the cell on its other side, and a porous diaphragm interposed between each insulating member and one of the adjacent conducting members, the juxtaposed face of the latter being recessed, whereby two compartments are formed in the cell, such recessed face of each conducting member being furthermore formed to present an irregular surface.

513. An electrolytic cell comprising two plates of carbon respectively adapted to act and cathode for, the cell, an annular separating plate of insulating material,

clamping means adapted to hold said sepa-' rating plate between said two carbon plates,

vconductors held in contact with the latter by said clamping means, the aperture in said separating plate being laterally inclosed by said carbon plates to form a closed chamber for the reception of the electrolyte and one of said plates being provided with ducts for the admission of the electrolyte to such chamclosed chamber and admission of the electrolyte her and theescape of gas therefrom, respectively, and means for controlling the pressure of the gas within the chamber.

14-. An electrolytic cell comprising two plates of carbon respectively adapted to act as anode and cathode for the cell, an annular separating plate of insulating material, clamping means adapted to hold said separating plate between said two carbon plates,

'conductorslicld in contact with the latter by said clamping means, the aperture in said separating plate being laterally inclosed by said carbon plates to form a chamber for the reception 'of the electrolyte, one of said plates being provided with vertically disposed ducts for the admission of the elec-. trolyte to such chamber and the escape of gas therefrom, means in connection with the first of such ducts for regulating the level of the electrolyte therein, and a gas seal for the second of such ducts. I

15. An electrolytic cell comprising two plates of carbon respectively adapted to act as anode and cathode for the cell, an annular separating plate of insulating material, clamping means adapted to hold said separating plate between said two carbon plates, conductors held in contact with the latter by said clamping means, the aperture in said .closed for draining the chamber, means for supplying electroljeteto the first .of such ducts, an adjustable overflow for regulating the level of the electrolyte therein, and a liquid seal for the second of such ducts.

16. In an electrolytic cell comprising a, closed chamber and having ducts for the admission of the electrolyte to such chamber and the escape of gas therefrom, the combination with. means in connection with the first ofsuch ducts for regulating the 'level of the electrolyte therein, of a gas sealfor the second of such ducts.

17. In an electrolytic cell comprising a having ducts for the to such chamber and the escape of gas therefrom, the combination of means "for supplying-electrolyte to the first of such ducts, an adjustable overflow for regulating the level of theelectrolyte therein,- and a gas seal for the 'second of such ducts. y t .18. An electrolytic cell comprising an annular plate of insulating material; two

plates of conducting material, respectively adapted to act asanode and cathode for the cell, clamped against opposite sides'of said annular plate and forming V therewith a chamber for the reception o'fthe electrolyte.

- cessed; anda diaphragm interposed between said annular plate and said cathode plate thereby dividing such chamber into two compartments.

19. An electrolytic cell comprising an annular plate of insulating inaterial; two plates of conducting material, respectively adapted to act as anode-and cathode for the cell, clamped against opposite sides of said annular plate and forming therewith a chamber for the reception of the electrolyte, the inner face of the cathode plate being recessed, and that of the anodeplate projectinginto such chamber; and'a diaphragm interposed between said annular plate and saidcathode plate thereby dividing such chamher into two compartments.

20. An electrolytic cell comprising an annular plate of insulating material; two plates of conducting material, respectively adapted to not as'anode and cathode for the cell, clamped against opposite sides of said annular plate and forming therewith a chamber for the reception of the electrolyte, the inner face of the cathode plate being grooved substantially vertically; and a diaphragm interposed between said annular plate and said cathode plate thereby dividing such chamber into two compartments.

21. An electrolytic cell comprising an annular plate of insulating material; two plates of conducting material, respectively adapted to act asanode and cathode for the cell, clamped against opposite sides of said annular. plate and forming therewith a chamber for the reception of the electrolyte, the inner face of the cathode plate being formed with a series of vertical grooves and with transverse grooves respectively connecting the upper and lower ends of such vertical grooves; and a diaphragm interposed between said annular plate and said cathode plate thereby dividing suchchamer into two compartments.

22. An electrolytic cell comprising an annular plate of insulating material; two plates of conducting material, respectively adaptedto act as anode and. cathode for the cell, clamped against opposite sides of said annular plate and forming therewith a chamber for the reception of the electro lyte, said cathode plate being provided with connecting ducts substantially parallel with its respective edges and having its inner face formed with a series of vertical grooves, the ends of thelatte'r being connected with the transversely disposed ducts in said plate; and adiaphragm interposed between said annular plate and said cathode plate thereby dividing such chamber into two compartments.

23. An electro ytic cell comprising an annular plate of insulating material; two plates of conducting material, respectively ing plates whereby closed c adapted to act as anode and cathode for the cell, clamped'against opposite sides of said annular plate and forming therewith a chamber for the reception of the electrolyte, said cathode plate being provided with connecting ducts substantially parallel-with its respective edges and having its inner face formed with a series of vertical grooves, and

with transverse grooves respectively connecting the upper and lower ends of such vertical grooves, such upper and lower ends being furthermore connected with the transversely disposed ducts in said plate; and a diaphragm interposed between said annular plate and said cathode plate thereby dividing such chamber into two compartments.

24. A series of electrolytic cells consisting of a plurality of plates of conducting material; annular plates of insulating material disposed one between each pair of conducting plates whereby closed chambers for the reception of electrolyte are formed, each such insulating plate being provided with ducts for the admission of the electrolyte to the corresponding chamber and the escape of gas therefrom, respectively, such escape being controlled by the pressure of the gas within the chamber; clamping means adapted to hold said conducting and insulating plates together, and conductors held in contact with the two terminal conducting plates by said clamping means, such terminal plates thus respectively acting as anode and. cathode for the corresponding cells and each of those intermediate between the ends acting as anode for the cell on its one side and as cathode for the cell on its other side.

25. A series of electrolytic cells consisting of a plurality of plates of conducting material; annular plates of insulating material disposed one between each pair ,of conducting plates whereby closed chambers for the reception of electrolyte are formed, each such insulating plate being provided with vertically disposed ducts for the admission of the electrolyte to the corresponding chamber and the escape of gas therefrom; means in connection with the first of such ducts for regulating the level of the electrolyte therein; a liquid seal for thesecond of such ducts; clamping means adapted to hold said conducting and insulating plates together,

and conductors held in contact with the two terminal conducting plates means, such terminal plates thus respectively acting as anode and cathode forthe corresponding cells and each of those intermediby said clampir ate between the ends'acting as anode for the" cell on its one side and as cathode for the cell on its other side.

26. A series of electrolytic cells consisting of a plurality rial; annular disposed one between each air of conduct-' ambers for the of plates of conducting mateplates of insulating material one side the chamber; means for supplying electrolyte to the first of such ducts; an adjustable overflow for regulating the level of the electrolyte therein; a liquid seal for the second of'such ducts; clamping means adapted to hold said conducting and insulating plates together, and conductors held in contact with the two terminal conducting plates by said clamping means, such terminal plates thus respectively acting as anode and cathode for the corresponding cells and each of those intermediatebetween the ends acting.

as anode for the cell on its one side and as cathode for the cell on its other side.

27. A series of electrolytic cells consisting of a plurality of conducting members, insulating' members disposed one between each pair of conducting members, and adapted jointly therewith to form a chamber for the reception of the electrolyte, the terminal conducting members respectively act-ing as anode and cathode for the corresponding cell and each of those intermediate between the ends acting as anode for the cell on its and as cathode for the cell on its other side, and a diaphra interposed between each insulating member and one of the adjacent conduct-ing members, the juxtaposed face of the latterbeing recessed, whereby two compartments are formed in the cell, such recessed face of each conductin memher being grooved substantially vertlcal.

28. A series of electrolytic cells consisting of a plurality of conducting members, insulating members disposed one between each pair of conducting members and" adapted jointly therewith to form a chamber for the reception of the electrolyte, the terminal conducting members respectively acting as anode and cathode for the corresponding cell and each of those intermediate between the ends one side and as cathode for the cell on its other side, and a diaphragm interposed between each insulating member and one of the adjacent conducting members, the juxtaposed face of the latter being recessed, wherev by two compartments are formed in the cell, such recessed face of each conducting member being formed with a series of vertical grooves connecting the upper and lower ends of such vertical grooves.

29. An electrolytic cell comprising two bipolar carbon electrodes and a separating member; secured therebetween, whereby a chamber for the electrolyte is formed.

30. Anelectrolytic cell comprising two bipolar carbon electrodes and a separating member and diaphragm secured between the same, whereby a divided chamber for the electrolyte is formed.

31. An electrolytic cell comprising two non-porous carbon electrodes and a separating member secured therebetween, whereby a chamber for the electrolyte is formed.

32. An electrolytic cell comprising two nonporous carbon electrodes and a separating member and diaphragm secured between the same, whereby a divided chamber'for the electrolyte is formed.

Signed by me this fourth day of December 1907.

THOMAS GRISWOLD, JR. Attested by- HELEN J GRIswoLn, LEO W. Lown.

Copies of this patent may be obtained for five cents each, by addressing the commissioner of Patents,

Washington, D. G.

acting as anode for the cell on its 

